Enhanced UV Photo-Stabilization of PBO Fibers via Sol-Gel Surface Modification

PBO fiber is the most excellent high performance fiber. But it is a kind of photosensitive material and is prone to degrade under ultraviolet (UV) radiation, which results in the changes of the fiber mechanical properties, finally affects the using of the material. In present paper, Titanium tetrabutoxide was used as solgel precursor of a nanosized TiO 2 coating to improve the photostability of PBO fibers. The nanosized TiO 2 coating was characterized by XRD. The influence of the coating on UV-durability of PBO was investigated by an accelerated UV-ageing method. Results of mechanical measurement showed that after exposing to UV light for 160 h, the fibers without TiO 2 coating degraded sharply, 7.01% of strength and 11.42% of break extension only remained, whereas 45.61% of strength and 68.56% of break extension still remained for the TiO 2 coated fibers. SEM analysis showed no significant surface morphological change on the coated fibers after the exposure, while some latitudinal crack fractures appeared on the uncoated PBO fibers.